fornes



March l0, 1964 G. G. FoRNEs. 3,123,970

ROVING PACKAGE: WINDING APPARATUS Filed April 25, 1961 4 Sheets-Sheet 1 FIG. 1

PRIOR ART lNVENTOR Gaston G. Fornes March l0, 1954 G. G. FoRNEs Rox/ING PAcAAz-E wINnING APPARATUS 4 Sheets-Sheet 2 Filed April 25, 1961 INVENTOR Gaston G. Fornes BY ,W

7 TTORNEYS March 10, 1964 G. G. FoRNEs 3,123,970

RovING PACKAGE WINDING APPARATUS Filed April 25, 1961 4 Sheets-Sheet 5 so 28 FIG. 3

P (42 [57 l umn A e2 l 4 I s3 *15| l 74 by; 72 /eo 77 22 78 24 :Il 23 neel` Il l v y I- I 25 :'51, 79

l` l INVENTOR i i I Gaston G. Fornes l BY 4 15% Am- 1, ATTORNEYS` March 10, 1964 G, GI FORNES 3,123,970

ROVING PACKAGE WINDING APPARATUS Filed April 25, 1961 4 SheetsSheet 4 los FIG.5

Hlll

INVENTOR Gos'ron G. Fornes ,Wal-Jam 7 ffy/@ATTORNEYS United States Pate-nt --iiice 3,123,970 Patented Mar. l0, 1964 This invention relates to roving frames used in the production of textile yarns and, more particularly to apparatus for winding packages of roving and the like to produce packages having greater density and stability.

Packages of textile roving are produced on roving frames. The packages are formed rby winding roving on bobbins in successive, closely wound layers. The bobbins are made to reciprocate axially so that the coils of each layer are wound seriatim. The amplitude of reciprocation of the bobbins and, hence, the length of each layer of roving are decreased during winding to provide package stability. Thus, a completed package of roving is generally cylindrical with tapered ends so that the end coils of each roving layer are supported by underlying layers in the package. Without this support, i.e. taper, the end coils would unlay and tangle requiring that the ypackage be unwound with diiiiculty or even discarded.

As is well known, a conventional roving frame comprises a plurality of drafting rolls for attenuating each Vof a large number of ends of sliver so that the number Vof fibers in cross section is reduced. The ends of roving are thenpassed to another part of the frame called the ilyer which puts a substantially Vuniform twist per unit length in the roving and then winds each end onto its own bobbin. The winding operation consists in laying the end of a roving on abobbin in successive layers, each layer consisting of a plurality of relatively closely-spaced coils wound around the bobbin. The twisting and winding operations are both accomplished with differential rotation between the rotating bobbin andthe flyer which rotates about the same axis as the bobbin.

In order that the coils be laid on the ybobbin side by side and in successive layers, the roving frame is provided with means which cause the bobbin to reciprocate axially with respect to the ilyer. As mentioned, for stability, a conventional roving frame is also provided with means which reduce by a xed and constant amount the amplitude of each successive reciprocation of the bobbin so that successive layers of roving wound on the bobbin have shorter lengths. The apparatus by which the amplitude of reciprocation of the bobbin with respect to the flyer is governed is called the builder, the construction of which is well known. Ordinarily, the biulder is actuated by, and in direct proportion to, motion of the so-ealled tension gearing.

Economic consideration dictate that as much roving yardage as is practical be wound on each bobbin. However, machines on which packages of roving are wound and later unwound are complex and expensive. Increasing package diameter is not practical for obtaining increased yardage per package because major modifications in these machines would be required.

In a copending application, Apparatus for Winding Packages of Roving and the Like, Serial No. 850,639 filed November 3, 1959, now Patent No. 3,021,664, I have discussed at length the mathematical relationships which must obtain between builder motion and the increasing diameter of roving layers being wound on the bobbins, to produce packages with tapered ends. For a detailed analysis, the reader is referred to that application.

Suiiice it to say, at this point, that in the conventional roving frame, decreases in roving layer lenght are made directly proportional to increases in roving layer diameter.

Vend tapers have signicant advantages.

The result is, of course, production of packages ofroving `having straight-line or` conically tapered ends.

Packages with conical tapered ends have been common for many years in the textile industry. However, recent studies have shown that packages with convexly curved Y Detalis of these studies are also .pointed out in the application referred to. Experiments with the conical end type packages also indicatethat mere increase in roving tension to provide `packages of greater density and greater yardage per unit volurneis notv helpful. Aggravated end coil stability problems arise which necessitate decreasing the slope of the taper, thereby introducing an offsetting reduction in total package volume.

But, when the tapers are made convexly curved, packaged volume and hence package yardage are directly increased. -Moreover,gstudies have shown that end coil stability can be enhanced with convex end sections by increased roving tension during winding. As a result, packages can be produced which have greater density and stability as well as significantly increased yardage.

It follows that, yto produce packages of roving with convexly curved ends tapers, the increases in roving layer vdiameter must be related to increasingly disproportionate reduction in roving layer length. Mechanisms which prouvidethisrelation automatically in a roving frame have been recently devised. They Work very well in producing 4roving packages with the advantageous convex en d tapers.

It is too early to know which type of these mechanisms will becomepopular in the textile industry. However, it stands to reason that any such mechanism which requires littleztime to produce and install; which requires 4small modification of existing frames; which is simple,

has few moving parts, and for which maintenance and replacement do not require extended roving frame stoppage will be preferred.

Satisfaction of all the above criteria in one machine probably represents a non-attainable goal of perfection. However, I believe I have invented apparatus that will satisfy more of these criteria than have been satisfied by previousdevelopments and which fall well within the practical limits of economics circumscribing the problem.

This invention provides apparatus which may be incorporated in existing roving frames to produce roving packages which have convex end tapers and increased roving yardage. The apparatus provided can be readily incorporated in an otherwise conventional roving frame. Further, the mechanism provided comprises lrelatively simple components which can be easily fabricated and installed. Installation of the new apparatus requires only minor roving frame modifications.

According to the invention, cam means and follower means are used to relate the proportional increases in roving layer diameter to the required disproportionate reductions in roving layer length. The cam means can include a generally rounded or generally elongated cam. The important feature is that the cam means and follower means combination include a camming dimension which changes in successively greater disproportionate amounts with respect to successive, equal increments, in a reference dimension.

Input means are provided for displacement of the cam means and follower means relative to each other in the direction or sense of the reference dimension upon completion of each layer of roving. This displacement is provided in successive, equal increments in proportion to successive increases in roving diameter. An output means is then arranged on the cam means for actuation in response to corresponding increasingly disproportionate differences in the camming dimension. The latter changes are utilized directly for controlling the amplitude of the succeeding bobbin reciprocation.

The input and output means can be hydraulically or mechanically actuated. They can also be electrically actuated in which case a cam such as a disc is not used, but, a cam-follower arrangement similarly utilizing disproportionately related differences in dimensions is provided.

The apparatus of this invention is easily fabricated and installed. Only minor roving frame modifications are required, namely, those of substitution of parts. Apparatus embodying this invention may be provided for installation in most commercial roving frames now in use. Frame operation is in the normal manner and no special operator attention is required.

With this invention roving packages can be produced with signcantly increased volume and yardage. ConveXly-curved package ends can be provided with any desired curve or profile. They can be made sinusoidal, parabolic, cycloidal, etc., by simply substituting cam-follower combinations of different sizes and contours. Fine adjustments in package profile can be obtained by providing for axial or olf-set center adjustment of the cam, when installed in the roving frame. Furthermore, with this invention in use, increased package density is attainable. Higher winding tensions can be used, which further increases package yardage, and the packages produced have improved stability.

These and other features of the invention will become evident upon reading the following, more detailed descriptions. For clarity, reference will be made to the drawings in which:

FIG. 1 is a schematic illustration of the builder mechanism of a typical, conventional roving frame;

FIG. 2 is an illustration of an embodiment of the persent invention, installed in the roving frame of FIG. 1, in which a at shoe cam and hydraulic means provide builder actuation;

FIG. 3 shows a second embodiment of the present invention in which a flat shoe cam and mechanical means provide builder actuation;

FIG. 3A is an enlarged elevational View, partly broken away, of a part of the builder mechanism shown in FIG. 3;

FIG. 3B is a sectional View taken along the line 3B-3B of FIG. 3A;

FIG. 4 is an illustration of a third embodiment of my invention in which electro-mechanical means provide builder actuation; and

FIG. 5 is an illustration of a fourth embodiment of my invention in which a fiat disc cam is installed to provide builder actuation.

Inasmuch as the construction and operation of conventional roving frames are well known it will not be necessary to describe the entire machine to illustrate the operation of apparatus according to my invention. A typical roving frame is fully described and illustrated in Hill: Cotton Drawing, Combing and Fly Frame Processes, published by International Textbook Company of Scranton, Pennsylvania. Accordingly, I will describe here only so much of a typical roving frame as is necessary to enable those skilled in the art to comprehend the details and features of a preferrred embodiment of the apparatus I have invented.

In FIG. l there is shown at 11 a portion of the bobbin rail of a roving frame which, as is well known, carries the bobbins and the bobbin rotating mechanism. Also, as is well known, the bobbin rail and all the mechanism mounted on it is driven up and down so that the bobbins on which roving is being wound are reciprocated axially with respect to the flyers. The flyers rotate with respect to the bobbins to put a uniform twist per unit of length in the roving and then wind it on the bobbin in successive layers, each of which consists of closely wound coils.

In order that the successive layers of roving wound on the bobbins are each shortened by a predetermined amount to form the appropriate tapered ends necessary for stability of the finished package of roving, a conventional mechanism known as a builder is used. To orient the reader and to facilitate understanding of the invention, and the manner in which embodiments of it are constructed and operated, there will rst be given a description of part of a conventional roving frame.

A conventional builder mechanism comprises a suitable bracket 12 mounted on the bobbin rail 11 which moves up and down. This bracket has a vertical portion 13 in which there are suitable tracks or other guiding means for an upper jaw 14 and a lower jaw 15. These jaws have substantially parallel, elongated, vertical camming surfaces 16 and 1'7, respectively.

A shaft 18, called the builder screw, is provided with two oppositely threaded portions 20 and 21. The upper jaw 14 is provided with internal threads which mate with the threaded portion 20 on the shaft 18 and the lower jaw 15 is provided with internal threads which mate with the threaded portion 21. Thus, because the threads on the portions 20 and 21 are oppositely directed, rotation of the shaft 18 in one direction or the other will either close or open the jaws upon each other to the extent permitted by the length of the threaded portions 20 and 21.

Adjacent and parallel to the shaft 18 there is a tumbler shaft 22 suitably mounted for rotation about its axis on a stationary part of the machine frame. A so-called builder dog, indicated at 23, is fixed to the tumbler shaft and has oppositely extending arms 24 and 25 which are of sufficient length in a radial direction so that the one turned toward the builder shaft will engage a vertical camming surface 16 or 17. It should also be noted here that the arms 24 and 25 are axially spaced from each other on the body of the dog 23.

The tumbler shaft is also provided with a spring-loaded camming mechanism 26 arranged to urge the tumbler shaft to rotate in a counterclockwise direction as viewed from the bottom of FIG. 1, thereby insuring that one or the other of the arms on the builder dogs will bear on the camming surfaces.

The tumbler shaft 22 is also positively, but intermittently, driven by the bevel gear 27 fixed to the upper end of the shaft 22 and the bevel gear 28 fixed to the main drive shaft 30 of the roving frame. As is well known the gear 27 is a sector gear having teeth in two opposite sectors and having no teeth in the other two opposite sectors. The gear 27 is so oriented on the tumbler shaft 22 that when one or the other of the arms on the builder dog is rotated into position to engage the camming surfaces on the builder jaws, a toothless sector on the gear 27 is adjacent or under the gear 28 on the main drive shaft so that there is no driving torque transmitted to the tumbler shaft.

Now, as the bobbin rail 11 is driven upward or downward to the end of its stroke the arm of the builder dog in engagement with the camming surfaces on the jaws will overrun the end of the camming surface so that there is no longer any resistance to the turning moment exerted on the tumbler shaft by the spring-loaded camming mechanism 26. This mechanism then causes the tumbler shaft to turn enough to bring a toothed sector of the gear 27 into engagement with the gear 28 and the tumbler shaft is positively and rapidly driven through nearly a half revolution before the next toothless sector of the gear 27 comes under the gear 28. By this time, however, the spring-loaded camming mechanism 26 is again in control of the tumbler shaft 22 and causes the shaft to complete the half revolution and bring the other arm of the builder dog to bear on the camming surfaces of the builder jaws. Thus, to illustrate, if the bobbin rail. is being driven downward while the arm 24 engages the camming surfaces, the tumbler shaft cannot turn untilA the arm 24, engages the cam surface 17 on the lower Y jaw 15.

Those who are acquainted with textile machinery know that the half revolutions of the tumbler shaft also actuate a mechanism which determines the direction in which the bobbin'rail is driven. yAtthe same time that the arm 24 overruns the end of the surface 16 and the tumbler shaft 22 turns through a half revolution, the driving mechanism of the bobbin rail is reversed by conventional means so that the bobbin rail is then driven upward. The upward travel will continue until the arm 25 on the builder dog overruns the lower end of the surface 17 on the lower jaw 15, whereupon the tumbler shaft will again be turned by the camming mechanism 26 and the gears 27 and 28. The bobbin rail driving mechanism will be reversed and the bobbin rail will again be driven downwardly.

As is apparent, these changes in direction of the bobbin rail travel result in the bobbins on all the spindles of the roving frame being driven up and down with respect to their respective iiyers which are axially stationary. With each reversal of direction of travel of the bobbin rail a new layer of roving is wound on each of the bobbins.

As has been previously described each successive layer of roving wound on the bobbin by a conventional roving frame is shortened by a predetermined and constant amount so that when the bobbin isfully wound the ends of the bobbin have a straight tapered shape. In conventional roving frames this is accomplished by turning the builder shaft by a predetermined amount in the direction which causes the upper and lower jaws 14 and `15 to close upon each other, thus bringing the upper and lower ends of the cumming surfaces 16 and 17 cioser together. Obviously, the upward and downward strokes of the bobbin rail are then shortened by a corresponding amount, for either the arm 24 will overrun the upper end of the surface 16 sooner than before or the arm `25 will overrun the lower end of the surface 17 sooner than before and cause the direction of travel of the bobbin rail to be reversed.

The conventional way of turning the builder screw by the necessary amount is to drive the builder screw from the tumbler shaft through a gear train which causes the builder screw to rotate through an angle which is in fixed and direct proportion to the angle through which the tumbler shaft rotates. This gear train, known collectively as the tension and taper gearing, comprises in order a worm gear 31 fixed to the tumbler shaft and spur gears 32, 33, 34 and 35. The gear 32 in engagement with the worm 31 is fixed to a shaft which is common to the gear 33. This latter gear engages the gear 34 which is fixed to a shaft common to the gear 35. The gear 35 engages the teeth 36 on the underside of an elongated rack gear 37. The rack gear is mounted on suitable guides so that it may be moved from side to side in FIG. 1.

Merely to orient the reader it is well to state here that this rack gear is also the driving element of a belt shipper mechanism for an endless belt which runs between the two cones or conical pulleys in the power train of the roving frame. The purposes of this power train are not directly relevant to this invention and need not be described in detail. However, the rackitself is also an element in the train of gears between the tumbler shaft and the builder screw.

A suitably mounted vertical shaft 38 carries the gears 4@ and 41, the former of which engages the teeth 42 along the side of the rack 37-as seen in FIG. l. The other gear 41 engages a gear 43 fixed to the builder V..6 screw shaft 18. The gear 43 and screw shaft 18 rotate together, but the screw shaft is of square cross-section and free to slide axially in an aperture in gear 43 as the shaft oscillates with the bobbin rail 11.

A mechanism of this kind can Vbuild bobbins having only straight tapered ends. While the taper angle may be changed by changing the various gear ratios within the mechanism, the machine is incapable of making other than straight tapers.

According to one embodiment of the present invention, the builder members 12, 13, 14, 15, and 18 are removed and-replaced by a new combination of elements shown in FIG. 2. Taper gear elements 33, 40, 41 and 43 may also be removed as they are not required.

In FIG. 2, hydraulic and mechanical means are used in conjunction with a flat, shoe cam 44. This cam is elongate with camming surfaces 45 and 46 at its longitudinal edges. The cam is mounted in the roving frame with its longitudinal axis parallel to the rack 37 which drives the belt shipper. The cam is rigidly attached by any strong supporting means to a roving frame structural member.

The camming portions or surfaces on opposite edges of cam 44 are symmetrical with respect to the longitudinal cam axis. `It is suiiicient, therefore, to describe one of the edge surfaces since the other is a mirror image of the first.

The upper camming surface 45 is best related to a system of cartesian coordinates. `In this system, with the horizontal axis parallel to the cam longitudinal axis, a reference dimension will be defined as the length of the cam. The total length is, for this embodiment, approximately equivalent to the length of the belt-shipper cones. A camming dimension will be defined as the width of the cam.

With the origin of the coordinate system lat the left end of the cam, the direction of increasing length will be to the right, along the horizontal axis. Now, for a conical taper on the roving package ends, the function relating ordinates and abcissas of the camming surface would be linear, i.e., the function would define a straight line with a positive slope. But, vfor the convexly curved tapered ends, this function is not linear.

For the latter case, the camming dimension, the cam width, increases in successively increasing increments as the reference dimension increases in successively, equal increments. Specifically, in the reference coordinates, the slope of the camming surface is positive and is progressively increasing.

The builder jaws 49 and 50 of this embodiment are mounted for relative motion on the member 11 of the frame which reciprocates in synchronism with the bobbin spindles. They are supported on the bobbin rail 11 by a T bracket 51. Two compression springs 52 and 53 are also mounted on bracket 51 with their axes coincident and parallel to the direction of reciprocation. The builder jaws have flange portions positioned against the outer ends of these springs. The springs, being in compression, provide a biasing for-ce exerted against the flanges which tends to move the jaws away from each other. These jaws also have elongate surfaces 16 and 17 similar to those in the conventional type of builder.

A hydraulic system is provided to drive the builder jaws together against the direction of the biasing force of the springs. The hydraulic system comprises cam follower pistons 54 and cylinders 55, and similar drive pistons 56 and cylinders 57. interconnected between the several cylinders is a network of tubing 58. Some of the tubes 59 in the network are, of course, flexible to allow for movement of follower cylinders SS as well as reciprocation of the drive cylinders. Also, the tubes Vand cylinders are filled with an incompressible fluid such as, for example, oil which is commonly used in such systems.

The cam follower cylinders S are rigidly mounted on a bracket 47 connected to rack 37 `for simultaneous movement therewith. The following pistons 54 are arranged to project against the camming surfaces 45 and 46 of the shoe cam with their axes co-linear. The drive cylinders and pistons are mounted on the reciprocating frame member 11 on opposite sides of the builder jaws. The drive pistons 56 project against the jaw iianges for moving the jaws together.

Operation of the system depends upon relative motion between the cam surfaces and the followers. At the start the rack is moved to the left and the followers bear against the narrow part of the cam. As the rack 37 moves in successive equal steps to the right, the follower pistons 54 are driven apart in directions transverse the direction of the longitudinal axis of the cam. This action increases the pressure exerted on the uid in the system which in turn causes the fluid to exert an increased force on the drive pistons 56. Thus, the flanges and builder jaws are driven together against the biasing forces of the spring.

The biasing force is also important in the reverse direction through the system. With this biasing force exerted through the ilanges on the drive pistons, the follower pistons are held, at all times, against the camming surfaces of the shoe cam.

Since the follower pistons are moved relative to their cylinders only in response to the successive changes in the width of the cam, as described above, the driving force exerted on the jaws 49 and 50 provides for closing movement of the jaws upon each other by amounts which are in direct proportion to the increasing changes in cam width.

The remainder of the roving frame is of standard construction. The usual builder dog rotates 180 upon one arm thereof overrunning a camming surface on one of the jaws, which causes the direction of reciprocation of the bobbin spindles to be reversed.

The package end profile which the builder jaws cause to be formed in this invention is a mathematically exact curve based on considerations analogous to that which I have described in the referenced application at pages 17, et seq.

The sine wave, ellipse, parabola, cycloid, involute and circle all have convex contours. The study of the properties of these curves to date indicates that the sine curve permits the use of a reasonable angle at the beginning of innermost layers, and it requires only moderate changes in the slope as the package is built. I will indicate herein, how my invention is adapted to produce an end taper fashioned after the sine curve to produce packages of roving with improved volume, density, stability and yardage.

Continuing study indicates to me that for winding different sizes of bobbins with different roving materials, and where roving diameter' will also be different, optimum roving tensions will also vary. With this in mind, it is apparent that the sine curve may not prove to be the best for all roving packages having convex end tapers. However, the cam actions of my invention can be readily adapted, by providing cams of different profiles, for production of convex end tapers after the fashion of the most advantageous geometric curve determined for particular roving packages. How this can be done will be readily apparent to those skilled in the art, after reading how it can be done for the sine curve case:

Along a mid-line of `a suitable work piece, measure a distance equivalent to the total length of rack movement. For the x 5 Saco-Lowell F .S. 2 roving frame this distance can be thirty inches.- The reference coordinate system is now defined with the x-axis along the measured mid-line with the origin at the left end of the measured distance. Thus x will vary between x0=0 and xm=30 inches.

Next divide the distance (xm-x0) into a convenient number of n equal increments. For illustration I will use n=10 but for accuracy in actual fabrication a higher number such as n=l00 should be used. Arbitrarily assigning unity value to xmzxn, tabulate normalized values of x from x0 to xnzl. Thus x0=0, x1=.1, x2=.2, x3=.3, and so on to xn=l.

Then tabulate corresponding angular values y from y0' to yn' from the relation of yzarc sin x. Thus y0='0, y1=5.7, y2=111.5, y3=17.4, and so forth to y'=9c.

A convenient minimum cam width must next be selected. In the l0 x 5 conventional frame of the example in the copending application referred to, it is seen that the diiference in lengths of the inside and outside roving layers is about 3.5 inches. This means that the builder jaws will move together by this amount or, one builder jaw will move 1.75 inches, 'along the builder screw.

Therefore a minimum cam width of 2 inches is a convenient value with which the maximum width will be around 5 1A. inches.

One can now calculate ordinate or y values from y0 to yn for the camming surface of the present example from the I'ialOIl y l y,

b (gul) where a=1/2 of the minimum cam width or 1 inch, and b represents the total range of y on (yny0)=l.75 inches. Thus y2=1.224, y3=l.340", and so forth to yn=2.750.

These values can be readily checked by slide rule. But, again, for actual fabrication, accuracy requires that many lmore ordinates be calculated. Also, the calculations should be done by logarithms so that ordinate values can be computed to the nearest ten thousandth of an inch.

Now the ordinate values can be plotted on the work piece, by standard techniques, so that a series of points (x, y) are located from (x0, y0) to (xn, yn). For the cam of the embodiment shown in FIG. 2, the lower camming surface 46 is laid out with the same ordinate values. But for this surface, the ordinate values are plotted in the negative y direction, i.e., a series of points (x, y) are plotted from (x0, -y0) to (xn, -yn) A smooth curve is next scribed through each set of points so that the camming surfaces can be cut and iinished by standard machine shop practices. Actually, the cam will be cut a few inches longer than the length (xn-x0) so that there will be sufficient material at each end for mounting purposes and for adjustment. The shape of the cam edges over such added end portions is not critical but there should be 11o abrupt changes in dimensions or curvature as the cutting operation is completed beyond the camming surfaces.

The calculations outlined above will produce an exact sine curfve profile on the cam edges. For practical application, modifications may be required before the cam is cut. As was discussed in the copending application previously preferred to (at page 19), one modification relates to provision of a straight line taper at the ends of the iinal roving layers because Of the rapidly decreasing radius of curvature of the sine curve as it approaches This can be provided in the present embodiment by scribing on the work piece the straight lines which are tangent to the sine curves at the points These lines are then followed in cuting, from the points of tangency, to the end of the cam, resulting in a slightly reduced value for y max. or yn.

Illustrated mathematically for upper camming surface 45, ordinate values beyond the point are computed from the relation y=c-|dx where c and d are constants to be evaluated.

Constant d represents the slope `of the tangent line to be drawn. That is evaluated by differentiating the function y: arc sin x=sin1 x once with respect to x and substituting the value of x at the point of tangenoy.

Thus

The value of y at 31:60", which is 2.165, is then substituted in the equation to evaluate constant c. Whence y60=c+(d) (xo)=2.l65=c|(2)(.8661), and the constant c is found to equl .433 inch.

Therefore, for the tenminal points of the camming surfacewhere xn--LO (normalized),

yn=.433 +`2(xn) :2.433 inches The tangent li-ne can then be drawn directly between the point (x=.866, y=2.l65) and (x='1l.0, y=2.433).

Another modification relates to the provision of optimum initial taper angle at the start Iof the winding operation. It was indicated at page 18 of the copending application referred to, how an initial taper angle of 571/2 degrees is suitable for :general purposes on the 10 x 5 frame.

Such a modification can also be provided in this invention. To do so in the embodiment shown requires scribing a straight line on the work piece, starting at the point (x=0, y0=1.0 inch), kat a slope equal to tan 321/2=.766\. Thus the equation of this line is If, for example, this taper angle is to be maintained for 1/5 of the roving package layers, the terminal point of this line is (x2=.2, y2=l.l53).

Appropriate adjustments can be made in subsequent calculations of the ordinate yvalues because now if the sine curve is to be followed from x2 to xn, the net change in y or (yn-y2)=1.597 inches as compared to 1.526 inches previously. This can be done rigorously by following mathematical reasoning similar to that previously discussed. `But =I have found that as a practical measure it is suficient if the two curves, i.e., the sine curve and the initial straight line, are joined in the vicinity of the ordinates at x2 by a smooth curve. The error introduced will be less than 7%, which is inconsequential, and may be as little as half of that amount if the curve is scribed by a skilled draftsman.

Of course the system of FIG. 2 is equally useful if the follower cylinders are rigidly mounted Kon a structural member of the roving frame with the cam supported for simultaneous movement with the rack. In this case the cam `i4 is simply reversed end for end from the position shown in FIG. 2.

The arrangements discussed would be for a hydraulic system with a mechanical advantage of unity. The areas of the cylinders and pistons can be provided so that the (y maxy min) value could be doubled, for example, while the distance of relative builder jaw motion remains the same. Also, a cam with only one camming surface could be provided in which case one follower piston would be arranged connected so as to actuate both drive pistons. How to construct apparatus for alternative arrangements such as these will be apparent to those skilled in the art.

Table I below is a compilation of the values computed for the sine curve illustration.

Table I x y=ar0 sin 1 0711's btw/rfa) t/=a+b(1l/yn) $0 =0 1,1/0 =0 O 0 yn =1.000 zr .1 y1:5.7 0.063 0.111 y. :1.111 z2 .2 y'. :11.5 0.128 0. 224 y2 :1.224 x3 .3 1/3 :17.4 0.194 0. 340 ya :1. 340 xr .4 y'. :23.6 0. 262 0. 460 yr :1. 460 x5 .5 ya :30. 0 0.333 0.583 ys :1. 583 xt .6 y :30.8 0.409 0.715 yt :1. 715 x7 .7 ya :44.5 0.495 0. ses 1/1 :1. 865 xr .s ya :53.1 0.590 1. 032 ya :2. 032 non: .850* y50:50.0 0. sse 1.165 @1600:2165 n .9 y'g :04.1 0.713 1.250 y., :2.250 xm :1. 0 y :90. 0 1.00 1. 75 ym =2. 750

*Reference point.

Another embodiment of my invention in which a iiat shoe cam 60, similar to the shoe cam 44 described above, operates a simple mechanical drive for closing the builder jaws is shown in FIG. 3. The shoe cam 66 is mounted to be traversed back and forth in the direction of its longitudinal axis by the reciprocating motion of the rack 37. It is also mounted for up and down motion with the rail 11.

To provide the back and forth motion and to permit the up and down motion a pair of vertically extending rods 64 and 65 are fixed at their upper ends to the rack 37 or an extension thereof. Angled braces 66 and 67 are fixed at their upper ends to the rack 37 and at their lower ends to the rods'64 and 65, for example by brackets 68 and 69, to

`brace the rods securely in their intended positions relative to each other. The shoe cam is equipped at its opposite ends with brackets 61 and 62. Each of these brackets has two spaced, coaxial sleeve bearings 63. The rod 64 is received in the bearings 63 on the bracket 61 and the rod 65 is received in the bearings 63 on the bracket 62. Thus as the rack moves left and right the rods which are rigidly fixed to it carry the shoe cam with the rack. As best seen in FIGS. 3A and 3B, a mounting frame 70, having a horizontal support plate 71, is fixed to the rail 11. A guide and actuating rod 72 passes through a vertical aperture in the support plate 71 and extends in both directions from the plate. At its upper end the rod has fixed thereto an upper cam follower 73 in which is mounted a cam follower roller 74 in a position to engage the upper camming portion or edge of the shoe cam. A lower builder jaw '75 is fixed to the lower end of the rod '72 and is provided with a camming surface 76 which extends parallel to the rod 72 and is generally similar in construction and purpose to the camming surface 17 on the builder jaw 1S previously described. In this arrangement the upper cam follower bracket 73, the rod 72 and the lower builder jaw 75 thus move as a unit.

vIn this embodiment I also provide a combined lower cam follower bracket and upper builder jaw illustrated at 77. A lower cam follower roller '78 is mounted in the bracket part of the member 71 in a position where it contacts the lower camming portion or edge of the shoe cam 64). The member 77 is also provided on its builder jaw portion with a camming surface 79 which extends parallel to the surface 76 and is generally similar in construction and function to the cam surface 16 on the builder jaw 14, previously described. The member 77 has an aperture through which the rod '72 extends but the rod and the member are free to move relative to each other; that is, the rod simply serves as a guide for the member 77.

An upper compression spring Sil is interposed between the support plate 71 and the member 77 and acts to urge the member upwardly. Similarly, a lower compression spring 81 is inserted between the support plate 71 and the lower builder jaw 75 and acts to urge the lower builder jaw 75, the rod 72 and the upper cam follower bracket '73 downwardly.

The cam follower rollers 74 and 78 engage the upper and lower edges of the shoe cam as previously stated and the springs 30 and 81 act to keep the rollers in er1- 1 1 gagement with the cam edges. Thus as the cam is drawn between the rollers, say from right to left, the cam forces the rollers apart and this in turn acts to bring the cam surfaces 76 and 79 on the builder jaws closer together against the forces exerted by the springs 80 and 81.

The sleeve bearings 63 in the brackets 61, 62 on the opposite ends of the shoe cam 60 permit the cam to follow the up and down motion of the builder mechanism as it reciprocates with the rail 11.

I aw closure is provided in successively greater increments as the cam followers are forced apart by relative, longitudinal cam movement. The novel mechanism just described cooperates with the builder dog 23 and the train of gears 31, 32, 33, 34 and 35 and the rack 36 in a conventional manner.

In a third embodiment of my invention shown in FIG. 4, electromechanical actuation of the builder drive is used. In this embodiment, the reference dimension, as defined in the discussion above, is the angle of rotation Which is always the same, through which the builder dog arms 24 and 25 rotate upon completion of each successive layer of roving. A conventional builder jaw mechanism is used for control of the builder dog. The builder dog performs in the usual manner, rotating through successive, equal 180 angles upon one arm thereof overrunning a camming surface on one of the builder jaws.

According to this embodiment, a pair of switches 91 and 92 are provided for alternate actuation by the builder dog arms. A rack 100 and pinion gear 97 are mounted in the frame for rotation of a builder screw shaft to close the paws. A template 93 on which a plurality of stop pins 94 are arranged is affixed to the rack. The camming dimension, again, as defined in the previous discussion, of this embodiment relates to the longitudinal spacing of the stop pins. The longitudinal spacing is provided in amounts which have successively greater differences from one end of the template to the other.

A relatively simple electrical arrangement results when the pins are aligned as shown in two rows on the template. Solenoids 95 and 96 are then mounted on opposite sides of the template with solenoid shafts projecting therefrom for engaging the rows of stop pins. In this situation, the pins of each row are longitudinally staggered. The solenoids are connected electrically to the switches at the builder dog. A tension linkage connected between one end of the rack and a stationary part of the frame completes the arrangement.

When the builder dog 23 and arms 24 and 25 rotate, one of the switches is closed thus energizing one of the solenoids. This causes the corresponding solenoid shaft to be withdrawn from the row of stop pins thereby releasing the rack 100 for motion in the direction urged by the tension linkage. The rack moves until the alternate solenoid shaft engages a stop pin in the opposite row on the template. As the rack moves, the worm gears 98 and 99, and builder screw shaft 18 are rotated to close the builder jaws.

This action is repeated by the second switch and solenoid when the builder dog again rotates, and so on. Each time the rack is advanced in successively greater amounts, as determined by the successively greater longitudinal spacing between stop pins. As a result, of course, the builder jaws are moved together in successively increasing increments which is the action required for producing roving packages with convex curved ends.

I will describe how a template with stop pins is fabricated so that the illustrative sine curve proile can be produced at the bobbins.

For simplicity, rack 100 is made similar to rack 37 of FIG. 1. Then the total distance, between the iirst and last stop pins will be equal to the distance moved by the belt-shipper rack during winding on the conventional roving frame. As previously stated, for a x 5 frame this distance is thirty to thirty-three inches. The

12 template piece 93 is provided slightly longer than this distance for convenience in mounting and adjusting.

Longitudinal location of the pins can be established several ways, based on the mathematical reasoning described previously. A very convenient method is available for this example when the taper gears 97, 98 and 99 provided have a conventional ratio so that the builder shaft rotates through a conventional total number of turns.

Lay off the total distance above, thirty to thirty-three inches, along the template center line. Then divide this distance into l0 equal increments. Then, starting with y0=0 at the right, and using the l0 increments as a scale, Where the last mark, yn, equals 1.00, the ordinate ratios from Table I, can be plotted directly along the center line or reference axis. Thus 310:0, y1:.063, y2=.128, y3=.l94 etc., to yn=1.00 at the left. Then two straight lines are scribed parallel to and above and below the center line. They can be conveniently scribed two inches apart, each being an inch away from the center line.

The y values are than projected perpendicularly from the center line or reference axis to the outer lines with y values for odd values of n being projected to one line and those for even values of n, to the other. The template is then drilled at the intersections of the projections and the outer lines so the stop pins can be mounted in staggered array along the template. (Or, the pins can be welded at the points indicated.)

Again, this is illustrative and many more than 10 pins will be required. Actually if 1z=the number of layers of roving, n+1 pins are necessary. But the above discussion will be adequate to shown how these pins are positioned.

Also, the two modifications described which provide for straight-line initial and final package taper can be readily incorporated in the stop-pin arrangement.

For the initial taper angle argument, taper gears 97 and 99 are selected so that subsequent, equal step-movements of rack 100 will result in builder jaw closure to provide the taper angle desired. This is within the skill of the present art. Then the first fifth of the template from y0 to y2 (assuming this initial angle will be maintained for the first fifth of the winding operation) is subdivided into m equal longitudinal increments where m= the number of roving layers to be wound over this initial range. These increments are then alternately projected to the upper and lower stop-pin lines. And, as previously, the pins are mounted in the alternate positions indicated.

For the straight line taper argument near the end of winding, say beyond y=.60 (specifically, for the last 30 of the sine curve or beyond y=.666 on the template), the remaining length on the template is divided into m' equal increments where m'=the remaining number of roving layers to be wound. These increments are then alternately projected to the stop-pin lines and the pins are mounted accordingly.

Another important embodiment of my invention, shown in FIG. 5, utilizes the relation of the previously defined reference and camming dimensions in a system of polar coordinates. A rotatable cam is used in this embodiment in connection with a chain drive for turning a conventional builder screw shaft 18 through successively greater arcs upon completion of each successive layer of roving.

In this embodiment a flat cam 105 and a wheel gear 106 are rotatably mounted on a common shaft. The shaft and wheel gear are mounted in the roving frame so that the wheel gear engages the belt shipper rack 37. As shown, an extension 107 on the rack can be provided to simplify location problems in the frame.

The periphery 108 of the cam 105 is of a prescribed contour. This contour is readily explained with reference to a system of polar coordinates in which the pole coincides with the geometric axis of the cam and in which the polar axis or initial line is positioned coincident with "13 'the shortest radius of thecar'n. The reference dimension in this case is the angle measured from the initial line (counterclockwise). The camming dimension, as I have defined it herein, is the length of any given radius from the pole or center of rotation 113 to the camrning surface 108.

Thus, in this cam, successive radii are of increasing length. Moreover, for any series of successive, equal angular displacements from the polar axis (or initial line), corresponding successive pairs of radii have successively greater differences in length. In other Words, for successive, equal changes in the value of the angle from the initial line, the corresponding differences in values of the lengths of radii (from the center of rotation to the camming surface) are successively greater.

The camming portion or surface contour 108 is advantageously formed as a smooth curve. This means that successive arcs of the contour, which are subtend equal angles at the center of rotation, areof successively greater length. Therefore if the cam is rotated (clockwise in the polar coordinates defined) through successive, equiangular displacements past a reference line, corresponding successive arcs which cross that line have lengths which differ by amounts which are increasingly disproportionate to the equal angular displacements.

For application of the changing camming dimension principle in this embodiment, the cam follower comprises a cable 109 which is wound on the camming surface. It follows that, as the cam is rotated through successive, equi-angular displacements by the rack 37 and gear wheel 106, successively increasing amounts of cable will be wound on the cam. The outer end of the cable is connected to a chain 110 which drives a sprocket 111 through successively increasing angular displacements upon cornpletion of each successive layer of roving. The taper gear train 4l and 43, driven by the rotating sprocket shaft, then operates to turn a standard builder screw shaft 18 for closing the builder jaws.

A tension linkage 112 attached to the other end of the chain, for keeping the chain taut and for resetting the mechanism between doffs, completes the arrangement.

Fabrication of a cam for this embodiment will be illustrated, again, for the Saco-Lowell FS 2, l" x 5 roving frame.

First a base circle is selected for the cam. I have used a base circle with a radius of 8 inches. A semicircle of this radius is then laid out on a pattern or directly on a work piece. For the reference system of polar coordinates, the center of the circle becomes the pole and, with the semicircle convex upwards, the initial line, r0=8 inches, lies horizontally to the right.

The semi-circle is then divided into n equal arc segments. Again, for illustration, I will use 11:10 although the greater the value of n selected, the more closely the cam surface will approach the desired contour.

Thus, l0 radii are drawn on the pattern at successive equal increments in the value of an angle 6 (measured counterclockwise from r around the pole). These increments in 0 are equal to 1r/l0 radians. Substituting 0/ 1r for X in Table I, we thus have a series of normalized values from Next a series of radius ratios, 1"/1r are computed from the relation 14 The values of these ratios from #0:0 to r'n are the same as those shown in column 3 in rTable I. Then a series of values for r from r0=0 to r=rn can be obtained from the Thus r0=0, r1=8(l.063)=8.504, r2=8(l.l28)= 9.025", r3=9.550, r4=10.09, r5=10.665, and so on to r10=16.00.

These values of r are marked along the successive correspending radii and a smooth curve is scribed through the ends of the radii so the cam can be cut from the work piece. Actually, the camming surface curve should be continued for a vertical distance of about two inches at each end so that more than the actual cam is cut from the work piece. This provides sufficient material for convenience in mounting and adjusting the cam in the frame.

Of course the camming surface can be provided in other shapes and with various modifications for particular bobbin profiles. The modifications previously described for initial and final taper angles can be provided. To do so on the cam illustrated, the mathematical reasoning previously discussed is applicable excepting that the same must be adapted for the polar coordinate situation.

After the cam is cut, the total length of the camming surface is measured, as with a tape so that a proper chain sprocket and taper gear ratio can be selected. This selection is within the present skills of the art and will not be explained further at this point.

A more rigorous analysis for developing the camming surface is also possible if one first selects the taper gear ratio and sprocket pitch diameter. Then, knowing the total number of turns required for the builder shaft during winding, the total camming surface length is determined from the relation S :21|- (pitch radius of the sprocket) (N) where N is the number of sprocket revolutions.

The base circle radius is selected and the semicircle is divided as before. Then a series of increasing arc lengths can be computed from the relation In polar coordinates, arc length is also expressed from the relation: ds2=dr2+ (rd0)2.

Subsequent values for r from r=r0 to rn can be developed using the two equations expressed. This analysis can be carried forward by those skilled in the mathematics and will not be developed here.

Concerning the electro-mechanical embodiment of my invention which I have described, other very advantageous forms can be provided where in the combination of cam means and follower means as broadly defined is ernployed to provide a reference dimension which is a constant value and a camming dimension which is a variable. One of these alternate forms requires negligible roving frame modification. Moreover, with this alternate form, the long-standard builder jaw mechanism can be eliminated. The builder jaws are replaced by limit pins and limit switches which are inexpensive to procure and install. This form is advantageous for installation when the builder jaws have worn out and would normally be replaced.

According to this alternate embodiment, two solenoids are arranged in lieu of the switches above described, for control of rotation of the builder dog. The solenoids are mounted in the frame so their shafts extend into the paths of the builder dog arms and are alternately engaged by them as the builder dog is rotated.

The builder shaft is mounted for rotation on the member of the frame which reciprocates in synchronism with the bobbin spindles. The axis of the shaft is disposed parallel to the direction of reciprocation. If necessary, an extension can be provided on the shaft to simplify location problems in the frame. The builder shaft herein is connected by the standard gear arrangements to the belt shipper rack for rotation. But, it does not have the usual builder jaws connected at its lower end. Rather, a series of limit pins are provided projecting in the radial directions from the shaft.

The principles of reference and camming dimensions as I have hereinabove defined are again applied. In this alternate embodiment, the reference dimension relates to the angular spacing between successive limit pins. The limit pins are positioned along radii of successively equal angular displacement around the builder shaft.

The cammining dimension relates to the longitudinal spacing between successive limit pins. The longitudinal spacing is provided in amounts which have successively greater differences from the first pin to the last. In other words, for illustration, the pins can be set perpendicular to the axis of the shaft, along a line on the surface of the shaft which defines a helix of continuously increasing pitch.

In this embodiment, two sets of these pins are located on the shaft spaced from each other in opposite longitudinal orientation. The pins of each set on the shaft are staggered by an angular amount equivalent to one shaft angular displacement.

A collar can be provided in which the pins are mounted. Such a collar provides increased circumferential distances for equal angular spacings between pins so that no two pins on one collar will be aligned parallel to the shaft axis. The collar can then be slipped on the shaft and held in place for movement therewith by ordinary key or set-screw means. A

Two limit switches are then arranged in the frame for actuation by the limit pins. The switches are electrically connected to the builder dog solenoids for alternate energizing.

As the builder shaft moves upward a limit pin will close the lower limit switch at the desired limit of upward travel of the bobbin spindles. Closing this switch energizes one of the builder dog sol-enoids. The corresponding solenoid shaft is thereby withdrawn from engagement with one of the builder dog arms. The builder dog and tumbler shaft are thus freed to rotate through the normal 180 arc, until the other builder dog arm engages the second solenoid shaft. As has been explained, this 180 revolution of the tumbler shaft causes the direction of the bobbin spindles to be reversed.

The builder shaft is rotated as in the normal roving frame, through successive equal arcs upon each builder dog and tumbler shaft revolution. The builder shaft revolution then places the next limit pin in line for succeeding actuation of the next limit switch.

The next limit switch is in turn closed when the succeeding reciprocation is at its zenith. The next solenoid is energized and the builder dog again rotates 180 to reverse the reciprocatory motion, and so on. Each time the builder shaft is turned (by successively equal angular amounts) the amplitude of the succeeding reciprocation is reduced. The differences in relative longitudinal spacing of the limit pins are increasingly disproportionate to the successive equal displacements of the builder shaft. Hence, the amplitude is continuously reduced in successively increasing increments, which is the action required for production of roving packages having convexly curved ends.

Still another electro-mechanical embodiment within the scope of the present invention involves a combination or" the two preceding electro-mechanicalI embodiments. In this case, the tumbler shaft is utilized only for reversing the direction of reciprocation of the bobbin spindles. Tension gearing and the belt shipper rack are also eliminated.

According to this embodiment, a template with two rows of stop pins, longitudinally staggered as before but with successively equal longitudinal spacing, is provided on a rack adapted for longitudinal movement by a tension linkage. Solenoid shafts are also arranged engaging the row of stop pins for limiting rack movement. Limit pins are arranged on the builder shaft as described above. Limit switches are again positioned for actuation by the limit pins.

In this embodiment, a selsyn generator is mounted on the tumbler shaft, with its rotor rigidly atiixed to the shaft. Successively greater decrements in the amplitude of reciprocation are controlled as before, with the limit switches each being electrically connected to a rack solenoid and to a builder dog solenoid. Each time a limit switch is closed, therefore, the builder dog rotates 180 and the rack advances, moving the builder shaft through successive equal angular displacements.

A selsyn motor, electrically connected to the generator, is used in this embodiment for advancing the belt shipper through successive, equal displacements in response to thc successive 180 displacements of the selsyn generator rotor on the tumbler shaft.

Still another arrangement is possible, by using a second selsyn motor geared to the builder shaft, which permits elimination of the above rack and template and stop pin solenoids. In this arrangement, the limit pins and limit switch are mounted as before for limiting the arnplitude of reciprocation of the bobbin spindles. Solenoids, energized upon closure of the limit switches, are again used for control of builder dog rotation.

Operation is as before with the added feature of the one selsyn generator being used to drive two selsyn motors. One selsyn motor is used to rotate the builder shaft and the other, to advance the bel-t shipper as described. The selsyn evolutions required are, as is evident from my previous discussion, all of successively equal amounts. Hence the generator rotor on the tumbler shaft can be used, electrically, to drive the two motors which, through appropriate gearing arrangements, displace the belt-shipper and builder shaft, by successive, equal, prescribed amounts.

Concerning the disc cam embodiment of FIG. 5, one important additional feature should be described. By providing an adjustable mounting apparatus at the shaft on which the cam and wheel gear 106 are supported, the axial position of the cam can be changed. This means that an operator, skilled in the use of these cams, can set the cam geometric axis to a predetermined position olf-set from the axis of rotation. With such a degree of mechanical freedom, fine roving package profile modifications can be obtained which further increases the utility of this embodiment.

I have described my invention in detail. Several embodiments discussed above are illustrative of what can be accomplished within the scope of my invention.

I claim:

1. In a roving frame, means for building packages of roving having curved end profiles which means comprises a fiat cam means having at least one camming portion, a cam follower mounted in said frame against each camming portion, each said cam follower being movable with respect to each said camming portion, each said camming portion having a contour which is prescribed in terms of camming and reference dimensions of the cam wherein, in a reference system of coordinates, the reference dimension is an independent variable and the camming dimension is a dependent variable, which dependent variable increases through successively increasing increments as said independent variable increases through successively equal increments, and means connected to a tension gear mechanism in said frame adapted to drive said cam means and each said cam follower relatively to cause each said cam follower to change its position with respect to each said camming portion whereby each said cam follower is displaced by successively increasing increments, the position of each said cam follower being adapted to determine positions of actuation of a frame l? mechanism which controls the lengths of successive layers wound on the bobbins.

2t. In a roving frame having bobbins mounted on a member of the frame yfor reciprocatory movement with respect to flyers, means including a tumbler shaft yfor reversing the direction of reciprocatory lmovement of said frame member upon completion of each layer of roving on the bobbins, 'tension land taper gear mechanism, including a rack, driven by said reversing means in successive equal increments upon said completion of each layer and a builder mechanism adapted for actuating said reversing means, the improvement which comprises a flat cam having at least one camming portion, a cam follower mounted in said frame `against each camming portion, each follower `being movable with respect to each camming portion, each camming portion having a contour which is prescribed in terms of camming and reference dimensions of said cam: wherein, in a reference system of coordinates, the reference dimension is an independent Variable and the camming dimension is a dependent variable, which camming dimension increases in successively increasing inorements as said reference dimension increases in equal lsuccessive increments, means connected to said gear mechanism and adapted to drive said cam and each cam follower relatively and thereby displace each cam follower by successively increasing increments, and means connected between each cam follower and said builder mechanism whereby the position of each cam follower is adapted to determine positions at which said builder mechanism actuates said reversing means.

3. The roving frame combination of claim 2 in which said cam is elongate with each longitudinal edge thereof comprising one said camming portion and one said cam follower is slidably supported against each said camming portion, Ithe upper `and lower of said camming por-tions being symmetrical with respect to the longitudinal axis of said cam.

4. The roving frame combination of claim 3 and in which each cam follower comprises a hydraulic cylinder and piston, one end of said pistons being slidably disposed against said camming portions, and drive cylinders and pistons are ldisposed in operative engagement with said builder mechanism, said drive cylinders being hydraulically connected to lthe cam follower cylinders by tubes filled with an incompressible fluid, Said drive pistons being movable in response to changes in positions of said cam `follower pistons on said cam.

5. The roving frame combination of claim 4 in which said cam followers are supported dependent from said rack for simultaneous movement therewith and said cam is rigidly mounted in said frame.

6. The roving `frame combination of claim 4 in which said builder mechanism comprises a pair `of builder jaws mounted on said frame member, said jaws comprising flange portions, said drive pistons being supported on said frame member and projecting against the outer surfaces of said flange portions, said jaws being movable together in response to motion of said drive pistons, and coil spring means supported on said frame member and projecting against the inner surfaces of said ange portions.

7. The roving frame combination of claim 3 and in which said cam is movably supported on said frame member, gear means are connected between said rack and said cam .for longitudinal displacement of said cam in successive equal increments in response to displacement of said rack, said builder mechanism comprises builder jaws mounted on said frame member, which jaws comprise flange portions, and coil spring means mounted on said frame member and projecting -against the inner sides of said flange portions, said jaws being biased by said spring means for separation movement, said cam yfollowers being rigidly connected to the said flange portions, said jaws being movable together in opposition to the l bias force of said spring mean-s in response to changes in the position of said cam followers on said cam.

8. The roving frame combination of claim 7 in which the cam follower at said lower camming surface is supported on one of said `flange portions and the cam follower at said upper camming surface is rigidly connected to the other of said ange portions, said cam followers being held against said camming surfaces by said bias force.

9. The roving frame combination of claim. 7 in which said gear means includes a second rack movably supported on said frame member and rigidly connected to said cam.

l0. In a roving frame having bobbins mounted on a member of the frame for reciprocatory movement with respect to flyers, means including a tumbler shaft for reversing the direction of reciprocatory movement of said frame member upon completion of each layer of roving on the bobbins, tension and taper gear mechanism, including `a rack, driven by said reversing means in successive equal increments upon said completion of each layer and a builder mechanism adapted for actuating said reversing means, the improvement which comprises a rotatable at disc cam having a peripheral edge camming portion, a cam follower, said cam follower being mounted in said frame against said camming portion, said cam follower being movable with respect to said camming portion, said camming portion having a contour which is prescribed in terms of camming and reference dimensions of said cam wherein, in a reference system of polar coordinates, the reference dimension 0 is an independent variable and the camming dimension "r is a dependent variable, which camming dimension increases in successively increasing increments as said reference dimension increases in equal rsuccessive increments, said cam being mounted in said frame on a shaft for rotation about an axis, means connected to said gear mechanism and adapted -to drive said cam and said cam follower relatively and thereby displace .said cam follower by successively increasing increments, a tension linkage one end of which is xed to said frame, and means in operative engagement lwith the other end of said linkage and connected to said cam follower for driving said builder mechanism, whereby the position of said cam follower determines the position at which said builder mechanism actuates said reversing means.

l1. The roving lframe combination of claim l() in which said means connected to said gear mechanism comprises an extension of said rack and a rotatable wheel gear mounted on said shaft and engaging said extension.

l2. The roving frame combination of claim l0 in which said cam follower comprises a flexible cable, one end of said cable being connected to said cam, said cable being wound on said camming portion by rotation of said cam.

13. The roving frame combination of claim l2 and in which said means connected to said cam follower comprises a chain one end of which is connected to the other end of said cable and the other end of which is attached to said tension linkage, and `a rotatable sprocket gear mounted in said frame and engaging said chain, said sprocket gear being connected to said builder mechanism, said sprocket gear being rotated in successively increasing angular increments by said chain when said cam -follower is displaced.

14. The roving frame combination of claim 10 and which further comprises means for supporting said cam on said shaft such that lthe distance between the geometric axis of said cam and the axis of rotation of said shaft is adjustable.

l5. In a roving frame, means `for building packages of roving having curved end profiles onto bobbins, comprising cam means having at least one camming portion, follower means mounted in said frame for each camming portion and adapted to be controlled thereby, each said followerv means being movable with respect to each said camming portion, said cam means and follower means having a reference dimension which is a constant value .and a camming dimension which is a. variable, which actuation of the frame mechanism which controls the lengths of successive layers Wound on the bobbins.

References Cited in the file of this patent UNITED STATES PATENTS 2,870,597 Hill et al Jan. 27, 1959 2,982,487 Newton May 2, 1961 2,996,870 Formes Aug. 22, 1961 3,019,588 Sanders et al Feb. 6, 1962 10 3,049,859 wise Aug. 21, 1962 FOREIGN PATENTS 139,061 Australia Oct. 17, 1950 UNITED STATES PATENT QFFICE CERTIFICATE OF CORRECTION Patent No. l3, 123,970 March lO, 1964 Gaston Gn Fornes It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l, line 70, for U'lenght" read length column 2, line 6, for "Detalis" read Details --5 line 69, after "roving" insert layer column 3, lines 35 and 36, for "persent" read present --5 column 6, line 40, for "abcissas" read absissas column 8, line 65, for "preferred" read referred line 75, for "outing" read cutting column 9, line 27, for "point" read points column ll, line 3l, for "paws" read jaws column l2, line 32, for "shown" read show Column 13, line 70, for l l .,l r /r read l l I n lines 7l to 75, for the left-hand portion of the ratio reading:

r read r I'nl L, n

column l4, lines 5 to 7, for that portion of the ratio reading:

r' r 5 Pnl read (rl n coluinn l5, line 13, for "cammining" read camming column 16 line 24, for "switch" Head switches column l7, line 46, fm "positions" read position Signed and sealed this 14th day of July l964.

(SEAL) Attest:

ESTON G, JOHNSON EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN A ROVING FRAME, MEANS FOR BUILDING PACKAGES OF ROVING HAVING CURVED END PROFILES WHICH MEANS COMPRISES A FLAT CAM MEANS HAVING AT LEAST ONE CAMMING PORTION, A CAM FOLLOWER MOUNTED IN SAID FRAME AGAINST EACH CAMMING PORTION, EACH SAID CAM FOLLOWER BEING MOVABLE WITH RESPECT TO EACH SAID CAMMING PORTION, EACH SAID CAMMING PORTION HAVING A CONTOUR WHICH IS PRESCRIBED IN TERMS OF CAMMING AND REFERENCE DIMENSIONS OF THE CAM WHEREIN, IN A REFERENCE SYSTEM OF COORDINATES, THE REFERENCE DIMENSION IS AN INDEPENDENT VARIABLE AND THE CAMMING DIMENSION IS A DEPENDENT VARIABLE, WHICH DEPENDENT VARIABLE INCREASES THROUGH SUCCESSIVELY INCREASING INCREMENTS AS SAID INDEPENDENT VARIABLE INCREASES THROUGH SUCCES- 